A report detailing corruption in the Customs and Border Protection service has revealed a group of officers used inside knowledge to bypass airport surveillance systems.

The interim report from the Australian Commission for Law Enforcement Integrity investigated allegations of collusion amongst four Customs officers at Sydney's international airport.

Between August 2012 and February 2013 the officers were arrested and charged with a string of offences including abuse of office, bribery and conspiracy.

The report found they used a network of contacts and their inside knowledge to thwart the airport's surveillance systems.

The commission found they started importing steroids in 2007 and later expanded the racket to include more officers and the precursor drug pseudoephedrine.

They allegedly developed friendships in order to gather information and cover their tracks.

Sixteen other people were also arrested during the crackdown and the report states further arrests are likely.

Home Affairs Minister Jason Clare says the report has prompted a raft of reforms at international airports across Australia including a ban on personal mobile phones in all controlled areas and regular officer rotations.

The head of the Customs and Border Protection, Michael Pezzullo, says the agency has also already started to take action.

He says the agency has introduced drug and alcohol testing and mandatory reporting of misconduct and corruption.

Liberal spokesman Michael Keenan says staff and budget cuts are partly to blame for the corruption.

"When you're reducing the agency's operating budget and reducing its ability to do its job, then that obviously takes a toll on the ability of the agency to resist corrupt overtures from organised crime," he said.

"That's clearly been a contributing factor in what is a scandalous occurrence of corruption within the Commonwealth Public Service."

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